Organizing a React component these days (H1/2018)

I started typing an answer to a question by @alexharrisonsax since my React book is written for the recent past (React 14) and things change. Twitter is not great for code discussions, so here goes.

Import dependencies

import React, {Component, Node} from 'react';

Declare the component

class App extends Component {}

Unless it's functional stateless component (preferably), in which case:

const App = ({name, description}) =>
  <div>
    <h1>{name}</h1>
    <h2>{description}</h2>
  </div>;

Flow

If using Flow, a good idea is to define the types of properties and state, like:

type Props = {
  name: string,
  description: string,
};

type State = {
  theTruth: boolean,
};

Then the class declaration becomes:

class App extends Component<Props, State> {
  state: State = { // property initializer for initial state
    theTruth: false,
  };

  // optional, only if the initial state is not good enough
  // or there are other things you need to do
  constructor(props: Props): void {
    super(props);
    this.state = { 
      theTruth: props.description === 'shall set you freeee',
    }; 
  }

  render(): Node {
    return <div>{/* fun with this.props and this.state */}</div>;
  }
}

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